Recent work from our laboratory has demonstrated that macromolecules such as plasmid DNA can pass into the intact lens, where they are localized in the lens epithelium. Based upon this observation, the overall hypothesis of this proposal is that plasmid DNA internalized in the whole lens can express therapeutically useful quantities of proteins such as the enzyme superoxide dismutase (SOD) and the lens epithelial derived growth factor (LEDGF). Both of these components protect against changes in gap junction activity and subsequent cataractogenesis that are caused by oxidative stress. The specific aims will be to 1) determine if the intact lens can be transfected in culture with LEDGF or SOD, using plasmids with various promoters including a lens-specific promoter that drives expression of LEDGF-GFP and SOD-GFP fusion proteins, 2) determine if expression of LEDGF or SOD in the whole lens will prevent cataract formation following exposure to [unreadable] hydrogen peroxide, an oxidative cataract model, or high glucose, a model for diabetes, 3) determine if the intact lens can be transfected with these same vectors by intravitreal injection of living rats. Together, these studies will test for the first time, the feasibility of using plasmids to alter the fundamental metabolism of the intact lens, through expression of therapeutically important macromolecules that will inhibit the oxidative processes thought to cause lens opacification. [unreadable] [unreadable] [unreadable]